HIGH-TEMPERATURE DIMENSIONAL REDUCTION OF THE MSSM AND OTHER MULTISCALAR MODELS IN THE SIN(2)THETA(W)=0 LIMIT

Using dimensional reduction we construct an effective 3D theory of the minimal supersymmetric standard model in the sin(2) theta(W)=0 limit at finite temperature. The final effective theory is obtained after th ree successive stages of integration out of massive particles. We obta in the full one-loop relation between the couplings of the reduced the ory and the underlying 4D couplings and masses. The procedure is also applied to a general two Higgs doublet model and the next to minimal s upersymmetric standard model.